JP2005115263A - Optical cable laying method and optical connection box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical cable laying method and an optical junction box which are compact and have good workability.
An optical junction box includes a main body and a lid that can be attached to and detached from the main body. The optical connection box holds an upstream gripping part that grips an upstream optical cable and a downstream optical cable. A downstream gripping portion; and a connecting portion holding portion that holds an optical connecting portion that connects the optical fiber derived from the upstream optical cable and the optical fiber derived from the downstream optical cable. The upstream gripping part 21, the connection part holding part 23, and the downstream gripping part 22 are arranged on the same straight line, and the optical fibers 14 and 15 are accommodated linearly in the optical connection box 10.
[Selection] Figure 1

Description

  The present invention relates to an optical cable laying method and an optical connection box, and for example, relates to an optical cable laying method and an optical connection box capable of connecting and branching an optical cable.

In recent years, the so-called FTTH (Fiber To The Home) service has been popular, in which an optical cable is drawn into a house or apartment, and connected to a device. The optical cable employs a method of making a small hole in the wall of the house from the outside and drawing it indoors, or drawing it in the same way as a telephone line and drawing it into the outlet.
In general, an optical connection box or the like for connecting an outdoor optical cable and an indoor optical cable is placed at the introduction port from the outside. This optical connection box is attached to the upper part of the wall, the outlet, and the like, and the optical connection box to the media converter are wired along the indoor wall like a coaxial line of a television.

As such an optical junction box, what is shown in FIG. 4 is disclosed (for example, refer patent document 1).
In the optical junction box 100, a cylindrical sleeve 101 that is configured to be split and has waterproof properties, a holding fitting 103 that grips the optical cable 102 at both axial ends of the sleeve 101, and an axial direction of the sleeve 101 extend. And a connecting plate 104 for connecting the holding fittings 103 to each other. Further, the sleeve 101 of the connecting plate 104 is installed in the axial center portion of the connecting plate 104, and the wiring portion 106 to which the optical fiber 105 led out from the optical cable 102 is routed is disposed opposite to both sides of the wiring portion 106. And a pair of tray storage portions 110 for holding a plurality of optical connection portion storage trays 109 for storing the optical connector 107 and its connection surplus length 108 in a stacked state.
Japanese Patent Laid-Open No. 9-274112 (FIG. 1)

  By the way, when the personal computer moves to another room due to room redesign or when the optical cable 102 is disconnected, the optical fiber 105 cannot be easily connected like a copper wire. It is necessary to connect a new optical cable 102 that is extended by providing the connection box 100. Further, when the optical cable 102 is connected to two personal computers, it is necessary to distribute the optical cable 102 into two using the optical connection box 100.

When the ends of the optical fibers 105 are connected to each other by a fusion splicing method, a mechanical splice method, or the like, the optical cable 102 from which each optical fiber 105 is led is attached to an upper part of a wall or an outlet port. Since the optical fiber 105 is gripped and fixed to the optical connection box 100, the operator takes out the optical fiber 105 from the optical connection box 100, performs the connection work, and then accommodates the optical fiber 105 drawn again in the optical connection box 100. There must be.
Therefore, a connection surplus length 108 for taking out the optical fiber 105 and performing connection work, distribution work, and the like is accommodated in the optical connection box 100 in advance.

Here, the connection extra length 108 is wound so as not to be bent below a predetermined radius of curvature when accommodated in the optical junction box 100, that is, below an allowable radius of curvature of the optical fiber 105 (for example, R = 30 mm). The optical connection box 100 that must accommodate such a connection surplus length 108 has a large outer dimension, which limits the installation space and deteriorates the appearance of the room.
Therefore, if you do not want the room landscape to be damaged, all the wiring up to the optical connection box in the in-house introduction part will be replaced, which will take time for replacement work and optical cables will not be used effectively. There was a problem such as.
Accordingly, it is an object of the present invention to solve the above-described problems, and to provide a compact optical cable laying method and an optical junction box that have good workability.

  In the optical cable laying method of the present invention, the optical connection portion connecting the optical fiber derived from the upstream optical cable and the optical fiber derived from the downstream optical cable is held in the connection holding portion of the optical connection box, and the connection portion The upstream optical cable and the downstream optical cable are gripped by the upstream gripping part and the downstream gripping part that are opposed to each other on the same straight line with the holding part interposed therebetween, so that the upstream and downstream sides of the optical connection part are respectively sandwiched. The optical fiber extending to the side is accommodated linearly in the optical junction box.

  The optical junction box of the present invention has a main body and a lid that can be attached to and detached from the main body, an upstream gripping part that grips the upstream optical cable, a downstream gripping part that grips the downstream optical cable, and the upstream An optical connection box that holds an optical connection part that connects an optical fiber derived from a side optical cable and an optical fiber derived from the downstream side optical cable, the optical connection box comprising the upstream gripping part and the The connection part holding part and the downstream gripping part are arranged on the same straight line.

  Preferably, the main body includes a fixing means for fixing the optical connection box to a fixed portion.

  Desirably, the upstream gripping portion and the downstream gripping portion each have a pair of optical cable locking pieces facing each other, and a plurality of locking protrusions are provided on the opposing surface of each optical cable locking piece. It is characterized by being.

According to the present invention, the optical fiber is linearly accommodated in the optical connection box by the upstream / downstream gripping part and the connection part holding part arranged on the same straight line.
Therefore, the optical connection box that accommodates the optical fiber that does not have a connection surplus length that is wound with an allowable curvature radius or more does not need to be provided with a housing portion that accommodates the connection surplus length. Since it is only necessary to have the minimum length dimension required, the outer dimension can be reduced.
Therefore, the optical connection box that is compact and has a good appearance can be installed at a desired place in the laying route of the optical cable.

Hereinafter, an optical junction box according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
1 is an exploded perspective view of an optical junction box according to an embodiment of the present invention, FIG. 2 is a plan view of a main body of the optical junction box shown in FIG. 1, and FIG. 3 is an optical connection shown in FIG. It is the partially broken top view which shows the accommodation state of the optical cable accommodated in the box, a partially broken front view, and a side view.

  As shown in FIG. 1, an optical junction box 10 according to an embodiment of the present invention includes an elongated rectangular plate-shaped main body 20 and an elongated rectangular box-shaped lid body 30 that can be attached to and detached from the main body 20. It has an elongated rectangular parallelepiped shape as a whole. The main body 20 and the lid body 30 can be made of plastic, but may be made of metal.

  As shown in FIGS. 1 and 2, on the bottom plate 20 a of the main body 20 inside the optical connection box 10, an upstream side gripping part 21 that grips the upstream side optical cable 11 and a downstream side that grips the downstream side optical cable 12. The holding part 22 and the connection part holding part 23 that holds the optical connection part 13 that connects the optical fiber 14 led out from the upstream optical cable 11 and the optical fiber 15 led out from the downstream optical cable 12 are arranged on the same straight line. Has been.

The upstream gripping portion 21 and the downstream gripping portion 22 provided at both ends of the bottom plate 20a are provided with a plurality of optical cable locking pieces 24 that are opposed to each other.
In the present embodiment, three optical cable locking pieces 24 project from each of the optical cable so that the upstream gripping part 21 and the downstream gripping part 22 can grip two optical cables. A plurality of locking projections 25 are provided on the opposing surface of the locking piece 24. Furthermore, the optical cable locking piece 24 of the present embodiment has a stepped shape with different facing widths at the upper part and the lower part, and is configured to be able to hold optical fibers having different diameters.

  The locking projections 25 projecting from the opposite surface of the optical cable locking piece 24 are ribs having a triangular cross section extending in a direction orthogonal to the optical cable to be gripped, and between the optical cable locking pieces 24 forming a pair. It bites into the jacket of the optical cable pushed in from above, and prevents movement in the longitudinal direction. In addition, a leading taper for facilitating the insertion of the optical cable is formed at the upper ends of these locking projections 25.

  Therefore, when a tensile force of an allowable value (for example, 5 kg) or less acts on the upstream and downstream optical cables 11 and 12 gripped by the upstream gripping portion 21 and the downstream gripping portion 22 of the optical connection box 10, the optical connection portion No pulling force acts on the optical fiber 13 and the optical fibers 14 and 15. The permissible value is at a level that causes no problem within the range where the optical cable is used indoors.

  The connecting portion holding portion 23 provided at the center of the bottom plate 20a is opposed to a support wall 23a suspended along the longitudinal center line of the bottom plate 20a and both side surfaces at both ends of the support wall 23a. And a clamping wall 23b that is arranged and elastically clamps the optical connecting portion 13. Therefore, the connection portion holding portion 23 can hold the two optical connection portions 13 on both sides of the support wall 23a.

Further, the bottom plate 20a is provided with a pair of screw holes 26, 26 as fixing means for fixing the optical connection box 10 to a fixed part such as an indoor wall, and is provided with an appropriate interval. The connection box 10 can be screwed. In addition, it can fix with other fixing means, such as a suction cup, a magnet, and a double-sided tape, instead of the screw hole 26.
Further, a lid locking piece 27 for locking the lid 30 at an appropriate interval is provided on the peripheral edge of the bottom plate 20a, and a locking portion 27a protruding outward is provided at the upper end. ing.

As shown in FIGS. 1 and 3, the lid body 30 is formed in an elongated rectangular box shape having an opening at the bottom, and the lid body provided on the main body 20 is disposed on both side walls 30 a and 30 a in the short direction. A locking hole 31 into which the locking portion 27a of the stopper piece 27 is fitted is provided.
Further, a pair of notches 32 through which the upstream and downstream optical cables 11 and 12 pass are provided at both longitudinal end faces 30b and 30b of the lid 30.

  Next, an optical cable laying method in the case where one upstream optical cable 11 is branched and distributedly connected to the two downstream optical cables 12 and 12 using the optical connection box 10 described above will be described. In the present embodiment, the upstream optical cable 11 is a two-core cable, and the downstream optical cable 12 is a one-core cable.

First, as shown in FIG. 1, the two optical fibers 14 and 14 led out from the upstream optical cable 11 are branched and connected to the optical fiber 15 led out from the downstream optical cable 12 and the optical connecting portion 13 respectively. . Here, as the optical connection part 13, the connection reinforcement part performed by the fusion splicing method or the mechanical splice method can be illustrated.
Then, as shown in FIG. 2, each optical connection portion 13 is inserted into the connection portion holding portion 23 provided in the main body 20 from above and elastically held, and on the same straight line with the connection portion holding portion 23 interposed therebetween. The upstream side optical cable 11 and the downstream side optical cable 12 are gripped by the upstream side gripping part 21 and the downstream side gripping part 22 that are arranged to face each other.

At this time, the optical fibers 14 and 15 accommodated and held in the optical connection box 10 are given some slack (about 5 mm) in order to alleviate a slight shift of the optical connection portion 13 and the optical cables 11 and 12. It is desirable. Thereby, even if the handling of the optical junction box 10 is somewhat poor, it is possible to prevent the optical fibers 14 and 15 from being disconnected inside.
When the optical junction box 10 is fixed to a wall or the like, the screw is passed through the screw hole 26 and fixed at a desired installation position.

Finally, as shown in FIG. 3, the lid 30 is placed on the main body 20, and the lid locking piece 27 of the main body 20 is pushed in until it engages with the locking hole 31 of the lid 30. And the lid 30 are integrated, and the mounting of the optical junction box 10 is completed.
When the optical connection box 10 is not fixed to a wall or the like, the upstream / downstream optical cables 11 and 12 to which the optical connection box 10 is attached are installed along a wall or the like in a desired installation route.

According to the optical connection box 10 of the present embodiment described above, the optical fibers 14 and 15 are connected within the optical connection box 10 by the upstream / downstream gripping parts 21 and 22 and the connection part holding part 23 arranged on the same straight line. It is housed in a straight line.
Therefore, an optical connection that accommodates the optical fibers 14 and 15 that do not have the connection surplus length 108 wound with an allowable curvature radius or more like the optical fiber 105 accommodated in the conventional optical junction box 100 shown in FIG. The box 10 does not need to be provided with an accommodating portion for storing the connection extra length, and only needs to have a minimum length required for connecting the optical fibers 14 and 15 to each other. it can.

For example, since the optical fibers 14 and 15 of the present invention do not have a surplus connection length, the distance between the upstream gripping portion 21 and the optical connection portion 13 in the optical connection box 10, and the connection portion 13 and the downstream gripping portion 22. The interval is determined by the length necessary for the operation of the connection method.
Therefore, when the current fusion splicer is used, the length in the longitudinal direction of the optical junction box 10 is about 155 mm, for example. If the required connection length becomes shorter in the future, the longitudinal dimension of the optical junction box 10 can be further reduced.

  Moreover, the width dimension and height dimension of the optical connection box 10 depend on the outer diameter of the optical cable and the size of the optical connection portion 13, and in the case of a two-core cable, the width dimension is, for example, about 20 mm, and the height dimension. Can be about 15 mm, for example. If the outer diameter of the optical cable and the size of the optical connection portion 13 are further reduced in the future, the width dimension and height dimension of the optical connection box 10 can be further reduced.

That is, the optical connection box 10 that has been compacted and improved in appearance can be installed at a desired place in the laying route of the optical cable.
Therefore, the optical cable once wired in the house can be further extended, or the disconnected optical cable can be repaired at the disconnection point.

In addition, the configurations of the main body, the lid, the upstream / downstream gripping portion, the connection portion holding portion, the optical cable locking piece, the locking projection, and the like in the optical connection box of the present invention are not limited to the configuration of the above-described embodiment. Needless to say, various forms can be adopted based on the gist of the present invention.
For example, in the above-described embodiment, the case where one upstream optical cable 11 is branched and connected to the two downstream optical cables 12 and 12 has been described. However, the number of optical cables to be connected is not limited to this. Is optional. In the above embodiment, the case of branching and connecting has been described, but the same applies to the case of simply extending the connection.

It is a disassembled perspective view of the optical connection box which concerns on one Embodiment of this invention. It is a top view of the main body of the optical junction box shown in FIG. It is a partially broken top view which shows the accommodation state of the optical cable accommodated in the optical junction box shown in FIG. It is a schematic plan view which shows the conventional optical junction box.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Optical connection box 11 Upstream side optical cable 12 Downstream side optical cable 13 Optical connection part 20 Main body 21 Upstream side holding part 22 Downstream side holding part 23 Connection part holding part 24 Optical cable locking piece 25 Locking protrusion 26 Screw hole (fixing means)
30 lid

Claims (4)

The optical connection part connecting the optical fiber derived from the upstream optical cable and the optical fiber derived from the downstream optical cable is held by the connection part holding part of the optical connection box, and on the same straight line across the connection part holding part By gripping the upstream optical cable and the downstream optical cable by the upstream gripping portion and the downstream gripping portion that are arranged to face each other,
An optical cable laying method, wherein the optical fibers respectively extending upstream and downstream across the optical connection portion are accommodated linearly in the optical connection box. An upstream gripping portion for gripping the upstream optical cable, a downstream gripping portion for gripping the downstream optical cable, and an optical fiber led out from the upstream optical cable; An optical connection box comprising: a connection holding unit that holds an optical connection connected to an optical fiber derived from the downstream optical cable,
The optical connection box, wherein the upstream gripping portion, the connection portion holding portion, and the downstream gripping portion are arranged on the same straight line.   The optical connection box according to claim 2, wherein the main body includes fixing means for fixing the optical connection box to a fixed portion. The upstream gripping portion and the downstream gripping portion are provided with optical cable locking pieces that are opposed to each other, and a plurality of locking protrusions are provided on the opposing surfaces of the optical cable locking pieces. The optical junction box according to claim 2 or claim 3, wherein

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